From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2010-04-16T06:25:08+09:00
Subject: Re: Ruby-warrior : Teaching AI concepts with Ruby

On Thu, Apr 15, 2010 at 10:00 PM, akraynov <akraynov@bk.ru> wrote:
> Hello guys! I consider RubyWarrior may be useful for learning. A have
> reached for 6'th level (as beginner).
>
> Now my code looks as following: http://good.net/_5pJ5Rurvz .
> I can't understand issue: if i call in method:
>    def roam_to_combat!
>      debug("Entering roam_to_combat")
>      state = :ws_combat
>      @ini_health = health
>      debug(@ini_health)
>      warrior.attack!(cur_dir)
>    end
>
> then it lacks to execute string "state = :ws_combat".
> But if i call
>    def roam_to_combat!
>      debug("Entering roam_to_combat")
>      self.state = :ws_combat # <-- here is difference
>      @ini_health = health
>      debug(@ini_health)
>      warrior.attack!(cur_dir)
>    end
> then it executes "state = :ws_combat" normally.
>
> Why it didn't execute "state =" without "self"?
> Is it Ruby's bug?
> I got Ruby 1.8 installed.

state = :ws_combat

is an assignment to a local variable. You are not using the variable
in the method, so i assume this is not what you want. When you do

self.state = :ws_combat

you are calling the method state= on the object, which I suppose you
have (maybe created by attr_accessor).

The fact that you have to call it this way is to disambiguate between
a local variable assignment and a method call with implicit receiver.
This is a consequence of the syntactic sugar that allows you have
methods name xxx= that look like assignments.

Jesus.